Many public safety agencies, such a police and firefighter departments, employ radio communication systems that use a conventional Carrier Squelch (CSQ) repeater system. For example a typical fire ground scene can have many firefighters on the scene, in close proximity, all transmitting uncontrolled on a single voice channel. One problem that can arise with concurrent usage is blocked transmissions. Any system which receives analog frequency modulated (FM) voice transmission which can receive multiple transmissions on the same channel simultaneously (by design or accident), such as message trunking systems, carrier squelch, or DPL/PL systems to name just a few, are susceptible to such transmission blocking problems. Under these conditions the multiple transmissions have relatively similar signal strengths. Accordingly, it would be desirable to have improved FM radio operation environments that provide for concurrent transmissions on the same channel without blocking transmissions.
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